package pro.softzhang.algo.lc100;

import pro.softzhang.algo.common.TreeNode;
import pro.softzhang.algo.flag.x.XClassic;

import java.util.ArrayList;
import java.util.List;

@XClassic
public class LC144_BinaryTreePreorderTraversal {
    public static void main(String[] args) {

    }

    static class Solution {
        public List<Integer> preorderTraversal(TreeNode root) {
            List<Integer> r = new ArrayList<>();
            if (root == null)
                return r;

            return null;
        }
    }
}
